This invention relates to amplifiers and, more specifically, to a radio frequency single-to-differential buffer amplifier which generates differential outputs having the same amplitude but 180 degrees out of phase.
One prior art single to differential amplifier is shown in FIG. 1. The differential amplifier shown in FIG. 1 will take a single ended radio frequency and convert it into a differential output. The amplifier in FIG. 1 works at low frequencies. However, at high frequencies, parasitic capacitances cause amplitude and phase mismatch.
Another prior art single to differential amplifier is shown in FIG. 2. The amplifier is driven by a single ended source. The signal is converted to a differential output by using a transformer. The problem with this differential amplifier is that it requires a transformer which when placed on-chip consumes significant amounts of valuable die area.
FIG. 3 shows another prior art single to differential amplifier. The differential amplifier depicted in FIG. 3 has some of the same problems as the previous prior art differential amplifiers. At high frequencies and high input power, the two output signals are no longer balanced. The two output signals will have phase and amplitude mismatch problems.
The prior art differential amplifiers have problems associated with operating at high frequencies and high power. This creates a need to provide a new single to differential buffer amplifier that can operate over a wide range of frequencies and power levels. The new single to differential buffer amplifier must be cost efficient and take up minimal amounts of die area.